Hi Cabe,
This IC runs the speaker in a differential or bridge configuration, that's why it can get away with not having a DC blocking capacitor on the speaker. If you want volume control I would recommend to replace R1 with and appropriately valued potentiometer and take the signal input to the chip from the wiper. Due to the amplifier's configuration I wouldn't add the pot on the speaker end, you will get better performance if you add the volume control near the beginning of the signal chain were currents are generally small and little noise will be created by the passive components.
hth,
Jorge Garcia
Hi Cabe,
This IC runs the speaker in a differential or bridge configuration, that's why it can get away with not having a DC blocking capacitor on the speaker. If you want volume control I would recommend to replace R1 with and appropriately valued potentiometer and take the signal input to the chip from the wiper. Due to the amplifier's configuration I wouldn't add the pot on the speaker end, you will get better performance if you add the volume control near the beginning of the signal chain were currents are generally small and little noise will be created by the passive components.
hth,
Jorge Garcia